!658 hw/display/ati_2d: Fix buffer overflow in ati_2d_blt (CVE-2021-3638)

From: @yezengruan 
Reviewed-by: @aven6 
Signed-off-by: @aven6

hw-display-ati_2d-Fix-buffer-overflow-in-ati_2d_blt-.patch

@@ -0,0 +1,82 @@
+From 05bd66416e58c3127b2a2fce8955a6f58ff34878 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= <philmd@redhat.com>
+Date: Mon, 6 Sep 2021 17:31:03 +0200
+Subject: [PATCH] hw/display/ati_2d: Fix buffer overflow in ati_2d_blt
+ (CVE-2021-3638)
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+When building QEMU with DEBUG_ATI defined then running with
+'-device ati-vga,romfile="" -d unimp,guest_errors -trace ati\*'
+we get:
+
+  ati_mm_write 4 0x16c0 DP_CNTL <- 0x1
+  ati_mm_write 4 0x146c DP_GUI_MASTER_CNTL <- 0x2
+  ati_mm_write 4 0x16c8 DP_MIX <- 0xff0000
+  ati_mm_write 4 0x16c4 DP_DATATYPE <- 0x2
+  ati_mm_write 4 0x224 CRTC_OFFSET <- 0x0
+  ati_mm_write 4 0x142c DST_PITCH_OFFSET <- 0xfe00000
+  ati_mm_write 4 0x1420 DST_Y <- 0x3fff
+  ati_mm_write 4 0x1410 DST_HEIGHT <- 0x3fff
+  ati_mm_write 4 0x1588 DST_WIDTH_X <- 0x3fff3fff
+  ati_2d_blt: vram:0x7fff5fa00000 addr:0 ds:0x7fff61273800 stride:2560 bpp:32 rop:0xff
+  ati_2d_blt: 0 0 0, 0 127 0, (0,0) -> (16383,16383) 16383x16383 > ^
+  ati_2d_blt: pixman_fill(dst:0x7fff5fa00000, stride:254, bpp:8, x:16383, y:16383, w:16383, h:16383, xor:0xff000000)
+  Thread 3 "qemu-system-i38" received signal SIGSEGV, Segmentation fault.
+  (gdb) bt
+  #0  0x00007ffff7f62ce0 in sse2_fill.lto_priv () at /lib64/libpixman-1.so.0
+  #1  0x00007ffff7f09278 in pixman_fill () at /lib64/libpixman-1.so.0
+  #2  0x0000555557b5a9af in ati_2d_blt (s=0x631000028800) at hw/display/ati_2d.c:196
+  #3  0x0000555557b4b5a2 in ati_mm_write (opaque=0x631000028800, addr=5512, data=1073692671, size=4) at hw/display/ati.c:843
+  #4  0x0000555558b90ec4 in memory_region_write_accessor (mr=0x631000039cc0, addr=5512, ..., size=4, ...) at softmmu/memory.c:492
+
+Commit 584acf34cb0 ("ati-vga: Fix reverse bit blts") introduced
+the local dst_x and dst_y which adjust the (x, y) coordinates
+depending on the direction in the SRCCOPY ROP3 operation, but
+forgot to address the same issue for the PATCOPY, BLACKNESS and
+WHITENESS operations, which also call pixman_fill().
+
+Fix that now by using the adjusted coordinates in the pixman_fill
+call, and update the related debug printf().
+
+Reported-by: Qiang Liu <qiangliu@zju.edu.cn>
+Fixes: 584acf34cb0 ("ati-vga: Fix reverse bit blts")
+Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
+Tested-by: Mauro Matteo Cascella <mcascell@redhat.com>
+Message-Id: <20210906153103.1661195-1-philmd@redhat.com>
+Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
+---
+ hw/display/ati_2d.c | 6 +++---
+ 1 file changed, 3 insertions(+), 3 deletions(-)
+
+diff --git a/hw/display/ati_2d.c b/hw/display/ati_2d.c
+index 4dc10ea795..692bec91de 100644
+--- a/hw/display/ati_2d.c
++++ b/hw/display/ati_2d.c
+@@ -84,7 +84,7 @@ void ati_2d_blt(ATIVGAState *s)
+     DPRINTF("%d %d %d, %d %d %d, (%d,%d) -> (%d,%d) %dx%d %c %c\n",
+             s->regs.src_offset, s->regs.dst_offset, s->regs.default_offset,
+             s->regs.src_pitch, s->regs.dst_pitch, s->regs.default_pitch,
+-            s->regs.src_x, s->regs.src_y, s->regs.dst_x, s->regs.dst_y,
++            s->regs.src_x, s->regs.src_y, dst_x, dst_y,
+             s->regs.dst_width, s->regs.dst_height,
+             (s->regs.dp_cntl & DST_X_LEFT_TO_RIGHT ? '>' : '<'),
+             (s->regs.dp_cntl & DST_Y_TOP_TO_BOTTOM ? 'v' : '^'));
+@@ -180,11 +180,11 @@ void ati_2d_blt(ATIVGAState *s)
+         dst_stride /= sizeof(uint32_t);
+         DPRINTF("pixman_fill(%p, %d, %d, %d, %d, %d, %d, %x)\n",
+                 dst_bits, dst_stride, bpp,
+-                s->regs.dst_x, s->regs.dst_y,
++                dst_x, dst_y,
+                 s->regs.dst_width, s->regs.dst_height,
+                 filler);
+         pixman_fill((uint32_t *)dst_bits, dst_stride, bpp,
+-                    s->regs.dst_x, s->regs.dst_y,
++                    dst_x, dst_y,
+                     s->regs.dst_width, s->regs.dst_height,
+                     filler);
+         if (dst_bits >= s->vga.vram_ptr + s->vga.vbe_start_addr &&
+-- 
+2.27.0
+

qemu.spec

@@ -1,6 +1,6 @@
 Name: qemu
 Version: 4.1.0
-Release: 74
+Release: 75
 Epoch: 10
 Summary: QEMU is a generic and open source machine emulator and virtualizer
 License: GPLv2 and BSD and MIT and CC-BY-SA-4.0
@@ -376,6 +376,7 @@ Patch0363: hw-scsi-lsi53c895a-Do-not-abort-when-DMA-requested-a.patch
 Patch0364: scsi-lsi53c895a-fix-use-after-free-in-lsi_do_msgout-.patch
 Patch0365: scsi-lsi53c895a-really-fix-use-after-free-in-lsi_do_.patch
 Patch0366: hw-usb-hcd-xhci-Fix-unbounded-loop-in-xhci_ring_chai.patch
+Patch0367: hw-display-ati_2d-Fix-buffer-overflow-in-ati_2d_blt-.patch
 
 BuildRequires: flex
 BuildRequires: bison
@@ -776,6 +777,9 @@ getent passwd qemu >/dev/null || \
 %endif
 
 %changelog
+* Fri Sep 30 2022 yezengruan <yezengruan@huawei.com>
+- hw/display/ati_2d: Fix buffer overflow in ati_2d_blt (CVE-2021-3638)
+
 * Wed Sep 07 2022 yezengruan <yezengruan@huawei.com>
 - hw/usb/hcd-xhci: Fix unbounded loop in xhci_ring_chain_length() (CVE-2020-14394)